Member postings for Les Jones 1

It would be better if you can provide information on the existing so we can tell you where to break the feed to the contactor coil. all of the interlocks, the thermal overload contacts and the stop button will probably be in series with the coil. Also we don't know if the contactor coil is powered between phases, between a phase and neutral or from the secondary of a low voltage transformer. Your existing wiring diagram should provide that information.

Les.

Reading through the thread again I notice you do have a contactor so here is a suggestion that would ensure the contactor dropped out when the switch passed through the middle off position.

Connect L1 directly to A on the motor.

Connect L2 to 6 and link 6 to 8.
Connect B on the motor to 5 and link 5 to 11

Connect L3 to 10 and link 10 to 12
connect C on the motor to 7 and link 7 to 9

Link 1 to 3 We will call this point X

Link 2 to 4 We will call this point Y

Break the feed to the contactor coil and connect the two ends of the break one to X and one to Y
This will cause the contactor to drop out when the switch passes through the middle off position.
You will then have to press the start button again after the switch has been set to either the forward or reverse positions.
As you have a contactor all three phases will be disconnected from the motor when the switch is in the off position.
Even if the switch is set to forward or reverse if the motor has been stopped with the stop button none of the phases will be connected to the motor. If you post the exiting wiring diagram and information on the contactor one of us will be able to tell you a suitable place to break the feed to the contactor coil.

Les.

Edited By Les Jones 1 on 24/01/2021 14:56:22

From the truth table Noel's instructions will only work in position 1. (Post 23/01/21 at 23:33)
It needs the following three links adding. 2 to 4, 6 to 8, and 10 to 12.

Edit. I see Martin has beat me to replying. His information will also work
Are you using a contactor and thermal overload ? If so the point made about arranging the wiring to make the contactor drop out in the middle off position is a good one. It would be even better is a delay circuit was added so that the contactor could not be activated for several seconds after it dropped out. This would prevent switching straight from forward to reverse.

Les.

Edited By Les Jones 1 on 24/01/2021 10:32:42

It looks like there is information on the left hand side of the switch between the connections. there is probably the same on the other side. If you post pictures of both sides it may avoid you having to meter out the connections.
The make and model number of the switch may enable use to find the data on the switch.

Les.

As John Rudd mentioned DON'T try to use a scope to fault find unless you supply the speed controller from an isolating transformer with a floating secondary. I suggest using a 60 or 100 watt incandescent light bulb as a load in place of the motor connected directly to the board. Also don't forget to link the connections that normally go to the interlock switches.

Les.

Here is a schematic for the XMT-2335 board in case you do not have one.

Arc Euro stock them under Seig X2 spares but they are £136.31.

Les.

Re my post on 08/01/21. The spindle that I ordered from China arrived today. There was nothing to pay.
(The collets that were ordered at the same time have not yet arrived.)

Les.

Just click on the camera button. (The next to last on the top line.)
That will display your albums and the picture files in them.
Select the file you want to display in your post and click on the OK button.

Have you measured the length of the belt path round the pulleys ? This would be a good approximation to the belt length.

Edit. I have just noticed your last post that you gave the number of teeth on the pulleys. These are the same as on the DB-10G.

Les.

Edited By Les Jones 1 on 09/01/2021 15:40:16

Edited By Les Jones 1 on 09/01/2021 15:41:17

I ordered one of these this morning as a result of LINK REMOVED (I also ordered a set of 15 ER11 collets for about £12.00) I too was wondering if there be additional charges when it arrives.

Les.

Edited By JasonB on 09/01/2021 06:57:51

Brian has said that a different length belt with the 1.5 pitch part of the specification seems to fit the pulleys.
(This wat in the post on the 7th at 12:40)

Les.

Edited By Les Jones 1 on 07/01/2021 20:25:43

Hi Jason,
I think it may be better if Brian confirms this measurement by using string or tape round the two pulleys in place of the belt before he orders one.

Les.

Many thanks Jason for explaining that. (I never even thought of dividing the measured pitch (In mm) by Pi.) The thread that Michael linked to suggests that the DB8 belt has 124 teeth. As Brian has given the diameter of the pulleys if he tells us the number of teeth on one of them we should be able to tell if the 1.5 pitch belt is the correct one.
One other point is that the Sieg C4a and C6 both use the same timing belt. This makes me think that the DB8 is based on a Sieg C4A and the DB-10G is based on the Sieg C6.

Les.

The belt for the DB-10G is called a 1.5 * 124 * 15. I think this is the same belt that is used on a DB8 lathe. I think the 1.5 part is related to the pitch but it does not seem to have any simple relationship with either metric or imperial units.

For comparison with the DB-10G the the small pulley (On the motor) has 19 teeth and the OD is 28.1mm. The large pulley has 90 teeth and the OD is 134.25 mm The distance between the pulley centres is 154mm.

Les.

Hi Michael,
Your link has given the required dimensions of the belt which is a good start as Brian does not seem prepared to to take any measurements. This seems to be the same belt as on my Chester DB-10G (Chester were no help when I needed to replace this belt.) When I measured the tooth pitch of my old belt I thought it was 3/16" (= 4.76mm) But I found it was called 5mm pitch which is probably what it is under tension. RS stock one that has the correct pitch (5mm) and number of teeth (124) but it is 16mm wide as opposed to the correct belt which is 15mm wide .Brian would have to measure the distance between the flanges on the motor pulley to see if this would fit.

Les.

Edited By Les Jones 1 on 06/01/2021 22:25:42

You can thread some string or tape round the two pulleys to get a rough idea of the length and measure the width of the pulleys to get a rough idea of the belt width. you may even have a piece of the belt that was still intact enough to measure the tooth pitch.

Les.

As John says if you measure the belt length, width and count the number of teeth there will be a much better chance of identifying the belt. I have a Chester DB-10G and it is just possible that it uses the same belt.

Les.

Andy. That is a good theory.
Nick, You could prove this by connecting a lamp or some other load to the lathe circuit. If that trips the RCD it probably proves Andy's theory. Tracing neutrals in a consumer unit can be difficult if it is fully populated.

Les.

I think John's and Nick's diagrams are probably correct. They are both functionally the same. The fact that the mains polarity is shown different does not matter. (Either way is OK.) If the motor rotates in the wrong direction then swap the power wire to the other white wire. (That is the Live in John's diagram. The neutral in Nicks diagram.) If you want to know what the thin black wires are then you will have to dismantle the motor. I can see three possibilities. They could go to a thermal fuse, A thermistor for monitoring the temperature. (This is not very likely on an old motor,) They may also may go to a centrifugal switch which disconnects the start winding when the motor gets up to speed. If it is a centrifugal switch it is faulty as it should measure almost zero ohms when the motor is stopped.
You could do a rough test of the capacitor by connecting it in series with a 60 or 100 watt incandescent lamp. (If you still have any of them.) The lamp should light but not quite as bright as when connected directly to the mains.

Les.

Hi Derek,
I can't remember the exact air pressure I use but I think is is only about 20 PSI. The nozzle is designed to suck up the oil but I use gravity feed to get a greater flow. I also heat the oil to about 100 degrees C so it atomises better. (The oil is not vaporised in the nozzle. it comes out as a fine mist. I use the water heater part of an old steam press to heat the oil. I start the burner with propane as the oil mist is not easy to ignite. Once started it burns without smoke. (But it is quite noisy.) I had to buy the nozzle from the US as I could not find a stockist in the UK.

Les.

I have made a waste oil burner for my furnace using a Hago Delavan syphon nozzle.
This is a link to the design of my burner but you will find some other designs on the web.
This is a link to the blower system I used.

Les.